My knees hurt . . .

I should probably be asking a doctor on this, but . . .

Yesterday's sprint triathlon went about like every one I've done: get out of the water in the middle of the pack, blow past most of my wave on the bike, and then watch them all pass me on the run. Mostly as I'm walking for decent stints because the pain in my knees is so bad I'm going to cry (probably because I weigh 230, and never do any real run training, because the pain in my knees is so bad I'm going to cry). And my ankles hurt, too. No past or known present injuries; I'm just a big guy who doesn't like to -- and thus never -- runs.

Is this something where, if I suck it up and run some miles over a few weeks, I'll build up some tolerance? 'Cause I'm sick of making it two-thirds of the way through the race in good shape and a good place, and then falling apart when I still have plenty of cardiovascular capacity but my leg joints feel like they've been hit with a hammer. If pushing through the pain in training will make it go away for further training and events, I'll do it. Otherwise, I'll stick with bike racing.

It sounds like you are not training to run but expecting to be able to. I started running at 220 and took it a little at a time. Do the run walk thing, and slowly build until you are running continuously. Running doesn't have to be so painful (well Ok, even the first mile is often a bummer for me but after I get warmed up it is really cool). I think you are hitting a brick wall because you haven't put in the time to break it down brick by brick first.

Have you tried to run for a minute and then walk for four and then run for 1 and walk for five with as much time as you can allow and then slowly change that to 2 minutes of run and three of walk. Then as you improve, you can change to 3 minutes of run with 2 minutes of walk and so on and so forth.

This should help you slowly get acclimated to running. You may also have joint problems and need to see a doctor.